Engine with stratified mixture



June 17, 1947. A, BAGNULO 2,422,610

ENGINE WITH STRATIFIED MIXTURE Filed Oct. 26, 1938 v 2 Sheets-Sheet l |NvENToR= ALBERT BAGNULO BY y ATTORNEYS June17,.1'947. ABAGNULO `2,422,610

ENGINE WITH STRATIFIED MIXTURE Filed oct. 2e, 1938 2 sheets-sheer 2 INVENTOR= ALBERT BAGNULO' BSL@ i ATTORNEYS Patented June 17, 1947 UNITEDY STATES PATENT OFFICE 2,422,610 ENGINE WITH s'rRA'1l1l1`1ni)yM'VIX'rUl'iEV Albert Bagnaia, Rome, nalyyvestea in the Attorney Generalof the United States Application october 26, 1938, serial No) 236,981 In France October 27, 1937 seetiens s and 1415ub1ic Laura90, August s, 1946. Patent expires October 27, 1957 3 Claims.

This invention refers to internal combustion engines utilizing a hot bulb and 'spark plug.

The objectof the invention is to provide an engine maintaining a high efficiency even at low load which is very flexible, robust, of normal weight andeasy to manufacture'. n

This object is attained by improvements in engines of a known type having a hot bulbseparated from the cylinder and operating with a medium compression ratio (of l the orderv of 7:1 to 1:1), and ignition controlled by sparking plugs (or equivalent means). fIfhe result of irnprovements. according to the invention is that tho richness of the combustible mixture in the bulb gradually decreases in the direction from the sparking plug tothe restricted passage connecting the interior of the bulb with the cylinder. This decreasing richness condition will be herein after referredr to asa mixture stratification.` y

In such an engine, the pure air drawn into the cylinder, and the fuel is injected in' atomised form into the combustion chamber either suction, or under pressure, according to the magnitude andthe nature of the force of molecular cohesion of the fuel. 4 l

An engine of this ^type operates in accordance with the cycle of explosion engines. Consequently, in order to achieve the object of the present invention it' will be necessary: A Y

l. To direct the jetof fuell in such a `rnan'ner that it is concentrated-about the sparking plug@ 2. To ensure, by suitable mixing, the formation of an explosive mixture without destroying the stratification. Y l n n v n 3. To protect the sparking plug from being soaked with fuel and from excessive temperature.

These conditions are fulfilled by suitably positioning theV injector and giving a predetermined form to the hot bulb. In the case of feeding,l under pressure, thejet is guided by asuitable inclination of the orifice of; the injector, Aand in the case of feeding suction by means of a defle'ctor disposed above Athe injection valve (see Figure l), The hot bulb has o n a cooled side a spherical or substantially spherical surfaceVA and on an unco'cled side aV spherical or substantially spherical surface of smaller diameter, these two surfaces being joined by a conical or concave surface, so that the entire chamber thus has a ovoidal profile; in addition, a projection is provided in the neighbourhoodl of theA sparking plug to protect it from the jetof fuel directed towards the plug, while a second projection or deflectorV is disposed to assist in imparting' aspiral movement to the gaseous'mixture. In thisrway, there' is imparted to the explosive mixture forced along by the air comingfrom the cylinder a centripetal spiral' movement, the effect of which is to vbring the richest zone of the mixture into contact with the sparking plug regardless of the quantity of fuel injected. d

In the accompanying` drawings, ywhich illustrate by way ofY example a constructional embodiment of the invention:

Figure' 1 is al cross-sectional view of the cylin-L der. head of an engine, n

Figure 2 illustrates the left-hand ypart of the pre-compression chamber seen in the direction of the arrows 2-2 of Figure 1; and

Figure 3 is a section on the line 3-3 of Figure `1.

Figure 4 illustrates a Amodification of Figure 1.

lThe ,hot bulb' chamber A constitutes a cavity, the right-hand part l` of which is of spherical formV while the left-hand part 2 has the form of a'cone completed' by' a sphere of smaller diameter, the chamber as a whole being thus ovoidal.` The port 3' for the admission of the air to the pre-combustion chamber is tangential with respect to'the spherical part I. The conical or tapered part 2, is disposed opposite to the air aclmiss'ionzport 3 and .lies at an angle of desired value thereto. rThe' sparking plug 4 is secured in anoriiice disposed at' the end of the conical part 2` rI he injector 5 is disposed at thev top of the` spherical part I 'opposite'to the port 3. This injector is formed, inthe case of inlet of the fuel by suction, by a valve` comprising a., deflector 9, and'y inthe case of the injection of fuel under pressureby a'd'evice of a known type lll (Figure 4), the oriiice ll of whichl is directed at a suitable angle. v

4Anprojection 6 extends downwards between the injector and the'sparking plug in the neighbourhood' of the point at which the generatrix of the cone tangent'ally meetsV the sphere 2, the said projectionr formingk aV screen which protects the sparking plug from the jet of fuel. A lip or deectorvfl extends' from the lower surface of the'k hotl bulb A in the region opposite the injector -5 and extends' over the interior of the edge of the tangentiall airwadmission passage 3, thesaid lip or deiiector adjacentthe conical part of the hot bulb' A' hai/insa thickness increasing over the wholewidth of the hotbulb in the direction of thepintercommunication passage 3. AVlhen the valve Eope'ns', the combustible, which is V-QIY Strongly projected in the, liquid stateJ towardjs the' small extremity 2"-of the hot bulb, accumulates there. The air charge which can 3 eventually accompany the combustible from the time of the introduction thereof, executed a gyratory movement in a counterclockwise direction, in accordance with the arrangement illustrated in Figure l. The combustible deposited on the hot wall of the hot bulb evolves vapour. The pure air, turned back across the tangential passage 3 assumes also a gyratory movement in the same direction as the first mentioned, but eccenl trically in relation thereto, owing to the orienta- Y tion of the air inlet and to thempresence ofthe deecting wall l. Apart from that movement, the air which is continually driven back of the cylinder to the hot bulb compresses in the direction of the sparking plug the gaseous mixture ypreviously introduced, the effect of which is to maintain the vapours in a region of thehot bulb hot bulb. Vthe engine can operate without regulation of the air, only the quantity of combustible introduced being varied. Upon slowing down, for..example,. when the quantity of combustible introduced is verysmall and the iilling of the cylinder is complete, the'operation is correct in spite of the great excess of air.

The stratication of the mixture is obtained bythe combined effectof the form of the hot bulb and of the general arrangement of the constituent elements thereof assuring the proper directionjof the jet of combustible; by the pressure of the turbulentair concentrating the combustiblevapor kin the small extremity of the hot bulb; and by. the device forthe deflection of the jet of combustible' aside from the sparking plug,

Itjwill thus be seenA that at the instant of the explosion initiated at thesparking plug the flame advances over an increasing volume ofthe chamberoand encountersizones of air of gradually increasing purity. The natural development of the ame'i's thus `assisted and the formation of disruptive .explosive waves such as occur in homogeneous mixturesis prevented.

Thev fuel consumption curve of such an engine shows a more accurate proportionality of the fuel consumption to the power developed, and oxidation phenomena due to delayed combustion owing toexcess of air are avoided.

Moreovenmeans are provided for increasing the temperature of the interior of the pre-com.. bustion chamber on the sparking plug side, since, the mixture being richer at this point, it is desirable to assist the gasification and to prevent condensationv in this region. With this object in View, theleft-hand half of the pre-combustion chamber isnot. provided with coolingmeans, but the right-hand part is cooled by means of recesses 8 through which circulates cooling water,

`It should be noted that, since the richness of the mixture must be maintained above a certain value in the neighbourhood of the sparking plug in order forthe mixture to be combustible, and

havingregardto the decrease in richness of the mixture` away'from this zone, an engine accordingjtojthe invention may be considered as being pulsion of land vehicles, while considerable advantages are obtained when the engine is employed for aircraft (operation during flight and operation on land). Moreover, when applied to the latter purposes, the engine according to the invention has the general advantage that due to l the absence of a Carburettor it eliminates the It is to be noted that the gyratory disadvantages due to freezing and the inuence of atmospheric conditions on the binary and ternary mixtures, and that it considerably reduces the danger of re even with highly inflammable fuels.

The invention is naturally capable of many different applications and modifications in construction apart from those referred to in the foregoing particular description which has been given in order to enable the nature and the scope of the invention to be readily understood.

What I claim is:

l. An internal combustion engine comprising at least one cylinder with piston, means to draw air into the said cylinder, a hot bulb of a generally ovoidal shape separated from the cylinder and interconnected therewith through a restrictedV passage opening tangentially with respect t0 thewalls of the larger end of said bulb, means to introduce fuel into the said hot bulb in order to form therein,` together with the air displaced by the piston through the passage, a combustible mixture, the said means comprising an injector the axis of which extends in a direction substantially perpendicular to the major axis of the ovoidal chamber, and a sparking plug mounted Vat the smaller end of the said ovoidal chamber.

2. An internal combustion engine comprising at least one cylinder with piston, means to draw air into the said cylinder, a hot bulb of a lgenerally ovoidal shape separated from the cylinder and interconnected therewith through a restricted passage openingrtangentially with respect to the walls ofthe larger end of said bulb, means to introduce fuelinto thesaid hot bulb in order to form thereintogether with the air displaced by the piston through the passage, a combustible mixture, the said means comprising an injector the axis of which extends in a direction substantially perpendicular, to the major axis of the ovoidal chamber, a sparking plug mounted at the smaller end of the said ovoidal chamber, and a projection located ahead of the sparking plug in order to protect same against the direct projections of fuel, the said projection having the form of a tongue, in a direction substantially perpendicular to the major axis of the said hot bulb, extending substantially as far as the said axis and having a mass suiciently small to maintain, by radiation of its heat, a very hot atmosphere Ain the neighbourhood of the sparking plug. Y Y

3. vAn internal combustion engine comprising atleast one cylinder with piston, ,means to draw air Vintothe said cylinder, a hot bulb of a generally ovoidal shapeseparated from the cylinder and interconnected .therewith through a restricted passage op.ening tangentiallyowith respect to the Walls of the larger end of said bulb, means to introduce fuel into the said hot bulb in order to form therein, together With the air displaced by the piston through the passage, a combustible mixture, the said means comprising an injector the axis of which extends in a direction substantially perpendicular to the major axis of the ovoidal chamber, the thickness of the Wall of the said hot bulb opposing the injector increasing progressively over the entire Width of the hot bulb in the direction of the intercommunication passage and forming in the neighbourhood of same a thick projection, in order to apply to the combustible mixture a rotary motion and to direct it towards the smaller end of the oVoidal chamber, and a sparking plug mounted at the smaller end of the said ovoidal hot bulb.

ALBERT BAGNULO.

REFERENCES siren The following references are of record in the ille of this patent:

UNITED STATES PATENTS Number Name Date 2,003,311 Ricardo June 4, 1935 1,691,182 Davol Nov. 13, 1928 1,942,127 Russell et al Jan. 2, 1934 1,967,243 Hesselrnan July 24, 1934 2,014,828 Wirrer Sept, 17, 1935 2,065,419 Bagnulo Dec. 22, 1936 FOREIGN PATENTS Number Country Date 400,173 Great Britain Oct. 12, 1933 

